<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>trimStart 与 trimEnd</title>
</head>
<body>
  <script>
    let str = '    iloveyou   '
    // 去除两侧空格
    console.log(str.trim())

    // 去除左侧空格 trimStart
    console.log(str.trimStart())

    // 去除右侧空格 trimEnd
    console.log(str.trimEnd())
  </script>
</body>
</html>